Many existing highway systems as well as substantial portions of the landing zones of air fields for receiving large and heavy aircraft are formed of reinforced concrete pavement. Inevitably, with the passage of time and upon subjection to various forces during use, even such reinforced pavement suffers deterioration and must eventually be replaced. Even otherwise, as when an existing highway must be replaced by a wider or sturdier highway to accommodate changing needs, existing reinforced pavement often needs to be removed and/or replaced.
Although numerous forms of pavement breaking apparatus and methods are in use today, they tend to be relatively inefficient and slow, at times labor intensive, and highly disruptive of existing traffic patterns. Known apparatus of this type ranges from the simple pick and shovel known since biblical times, through pneumatic or hydraulic jackhammers and front end loaders that require skilled personnel to operate safely, to assorted power-driven multi-bladed devices that more or less chop up existing pavement in place to serve as a base for an additional layer of fresh pavement thereon. Such apparatus and methods for using the same leave much to be desired.
U.S. Pat. No. 4,692,058 to Mengel, issued on Sept. 8, 1987, discloses apparatus and a method for removing pavement wherein an acute-angled wedge, wider than pavement that is to be broken up and removed, is forced under the pavement to exert a force to lift it off the underlying ground. lA heavy, pivoted, and preferably hydraulically driven hammer hits the pavement above the front edge of the wedge and cracks the pavement at every few inches of its length by generating tensile forces in the lower portions of the lifted pavement under the applied impact force. A second hammer having a saw tooth impact surface profile thereafter renders the cracked pavement and any tensile reinforcement material included therein into smaller pieces but does so without separating the bulk component of the reinforced pavement, e.g., concrete material, from the tensile reinforcement material, typically steel bars or netting. In this apparatus, the acute-angled wedge rests on the underlying ground from which packed pavement has been lifted by the wedge, the heavy hydraulically driven hammer is pivotably supported on a ramp drawn directly behind the wedge to force the wedge under the approaching pavement.
A need exists for apparatus and a method that can in a single pass rapidly and economically break up a substantial width of existing pavement to totally remove the same from the underlying ground while simultaneously separating the bulk component of the pavement from relatively valuable reinforcement material and for rendering both components into small pieces that are more easily handled and, therefore, more useful forms thereof. Preferably, these rendered constituents are immediately but selectively utilized in combination with other suitable materials, to lay down replacement pavement.